1. Field of the Invention
The present invention relates to a communication system, in which a server device informs an access point of an encipher key used when a client terminal performs communication through the access point.
2. Description of the Related Art
Conventionally, in a wireless LAN system, a client terminal has been connected to a network through wireless communication with an access point on the network.
There is also a wireless LAN system, in which a client terminal receives authentication of connection to a network through an access point from an authentication server on a network.
In such a system, when the client terminal receives authentication from the authentication server, the client terminal and the authentication server create an encipher key of a wired equivalent privacy (WEP) encipher system, and the authentication server informs the access point of the created encipher key. Then, the client terminal transfers enciphered data with the access point by using the encipher key of the WEP encipher system to perform secure wireless communication.
Incidentally, a communicable range of the access point is limited to a range reached by electric waves. On the other hand, the client terminal can be freely moved. Accordingly, the client terminal may be moved from a communicable range of an access point 1 to a communicable range of an access point 2. In this case, the client terminal must receive authentication of connection to the network from the authentication server again through wireless communication with the access point 2, the client terminal and the authentication server must create a new WEP key, and the authentication server must inform the access point 2 of the new WEP key.
That is, when the client terminal changed the access point, re-authentication from the authentication server, creation of a new WEP key, informing of a WEP key, and the like prolonged the process until communication became possible. Consequently the process took time.
In addition, in a system of many client terminals, since authentication and creation of a WEP key prolonged a process, a load on an authentication server inevitably became large.
Furthermore, since the process took time when the access point was changed, usability was reduced.